Off-board fuel regulator for generator engine

ABSTRACT

A generator and off-board fuel delivery system is disclosed. The generator is configured to operate on one or more fuels, including on a gaseous fuel supplied from a pressurized fuel source through a gaseous fuel line. A fuel regulator system is located off board the generator and is configured to regulate the gaseous fuel supplied from the pressurized fuel source in a first stage, with the gaseous fuel regulated down to a reduced pressure in the first stage. A second stage of the fuel regulator system regulates the reduced pressure gaseous fuel, with the reduced pressure gaseous fuel from the first stage regulated down to a desired pressure in the second stage for delivery through the gaseous fuel line to operate the generator.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of, and claims priority to,U.S. patent application Ser. No. 16/191,503, filed on Nov. 15, 2018,which is a continuation of, and claims priority to, U.S. patentapplication Ser. No. 14/738,060, filed on Jun. 12, 2015, now U.S. Pat.No. 10,221,780, issued Mar. 5, 2019, the disclosures of which areincorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Embodiments of the invention relate generally to dual fuel generators,and more particularly, to an apparatus and method for delivering liquidfuel and gaseous fuel to a dual fuel generator.

Electric generators are frequently driven by internal combustion enginesthat use gasoline as a fuel source. Gasoline is a common fuel source forgenerators in a variety of applications. However, alternative fuelsources also provide a desirable fuel source. For instance, alternativefuels may provide a clean burning fuel that limits hazardous emissions.Alternative fuels may also be stored for long periods of time withoutdegradation, whereas gasoline can degrade over a period of monthsleading to hard starting, rough running, and also lead to gum andvarnish deposit left in the fuel system. In addition, generators thatoperate on alternative fuels may generate electricity when gasoline isnot readily available. For instance, generators are frequently used whenpower outages in the utility grid result from severe weather.Unfortunately, gas stations may also be closed as a result of the poweroutage. Such a circumstance presents just one example where it would beadvantageous to operate electrical generators on alternative fuels.

Certain generators are configured to operate as “dual fuel” generators,otherwise known as bi-fuel generators. These generators are driven by aninternal combustion engine that is configured to operate on a liquidfuel for a period of operation and an alternative fuel for anotherperiod of operation. The alternative fuel source may exist in a gaseousstate at normal temperature and pressure and can be any one of liquefiedpetroleum gas, compressed natural gas, hydrogen, or the like. Liquefiedpetroleum gas (LPG), often referred to as propane, exists in a gaseousstate at normal temperature and pressure but can be conveniently storedunder pressure in a liquid state. LPG may be a desirable fuel source forinternal combustion engines because it can be stored for longer periodsof time and contains fewer impurities than gasoline, resulting insmoother and cleaner operation, and often resulting in a longer lastingengine.

In order to provide the liquid and gaseous fuel to the engine, the dualfuel engine may have a first fuel line for liquid fuel and a second fuelline for gaseous fuel. A liquid fuel source and a gaseous fuel sourcemay be coupled to the respective lines to provide fuel to the engine.However, a common problem with such configurations that couple two fuelsources to a single engine is the engine can experience overly richair-fuel ratio when both fuels are simultaneously engaged duringcross-over switching between the fuel sources. Further, suchsimultaneous delivery of fuel from the first fuel line and the secondfuel line may make the engine hard to start or lead to unstableoperating conditions.

Therefore, it would be desirable to design a dual fuel generator havinga liquid fuel and gaseous fuel delivery system that overcomes theaforementioned detriments without substantially increasing the overallcost of the system.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with one aspect of the invention, a mechanical fuellockout switch for a dual fuel engine provides for the selection of adesired fuel to operate the engine. The mechanical fuel lockout switchincludes a mechanical fuel valve and a fuel lockout apparatus. Themechanical fuel valve actuates between a first position and a secondposition to selectively control fuel flow to the dual fuel engine from afirst fuel source through a first fuel line and a second fuel sourcethrough a second fuel line. The fuel lockout apparatus couples to themechanical fuel valve ensuring individual communication of the fuelsources to the engine. The mechanical fuel lockout switch communicatesthe first fuel source to the dual fuel engine and prevents communicationbetween the second fuel source and the dual fuel engine when themechanical fuel valve is in the first position, and communicates thesecond fuel source to the dual fuel engine and interrupts the first fuelsource communication with the dual fuel engine when in the secondposition.

In accordance with another aspect of the invention, a dual fuelgenerator and fuel delivery system includes a dual fuel generatorconfigured to operate on a liquid fuel supplied from a liquid fuelsource through a liquid fuel line and a gaseous fuel supplied from apressurized fuel source through a gaseous fuel line. The dual fuelgenerator and fuel delivery system also includes a fuel regulator systemlocated off board the dual fuel generator to control the pressure offuel from the pressurized fuel source and deliver the fuel at a desiredpressure for operation of the generator. The fuel regulator systemincludes a primary pressure regulator coupled to a service valve of thepressurized fuel source and configured to regulate the fuel suppliedfrom the pressurized fuel source to a reduced pressure. The fuelregulator system also includes a secondary pressure regulator coupled tothe primary pressure regulator and configured to regulate the gaseousfuel supplied from the primary pressure regulator to a desired pressurefor delivery through the gaseous fuel line to operate the dual fuelgenerator. The dual fuel generator and fuel delivery system furtherincludes a mechanical fuel valve actuatable between a first position anda second position to selectively control fuel flow to the dual fuelgenerator from the liquid fuel source through the liquid fuel line andthe pressurized fuel source through the gaseous fuel line.

In accordance with yet another aspect of the invention, a method ofassembling a mechanical fuel lockout switch for an internal combustionengine includes providing an internal combustion engine configured tooperate on a fuel from a first fuel source and a different fuel from asecond fuel source. The method also includes coupling a mechanical fuelvalve to the internal combustion engine actuatable between a firstposition and a second position to selectively control fuel flow to theinternal combustion engine from the first fuel source through a firstfuel line and the second fuel source through a second fuel line. Themethod further includes coupling a fuel lockout apparatus to themechanical fuel valve. When the mechanical fuel valve is in the firstposition, the fuel lockout apparatus communicates the first fuel sourceto the internal combustion engine and prevents the second fuel sourcefrom coupling to the internal combustion engine, and actuation of themechanical fuel valve to the second position causes the fuel lockoutapparatus to permit the second fuel source to couple to the internalcombustion engine, and interrupts the first fuel source communicationwith the internal combustion engine.

Various other features and advantages will be made apparent from thefollowing detailed description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate preferred embodiments presently contemplated forcarrying out the invention.

In the drawings:

FIG. 1 is a perspective view of a dual fuel generator coupled to a fueldelivery system, according to an embodiment of the invention.

FIG. 2 is a detail view of a portion of the generator of FIG. 1 about amechanical fuel lockout switch with the switch in a first position,according to an embodiment of the invention.

FIG. 3 is a detail view similar to FIG. 2 and showing the mechanicalfuel lockout switch in a second position, with an LPG supply lineconnected thereto, according to an embodiment of the invention.

FIG. 4A is a schematic diagram of a fuel system for the dual fuelgenerator of FIG. 1 showing a liquid fuel source in communication with acarburetor of the generator consistent with the first position of theswitch as shown in FIG. 2, according to an embodiment of the invention.

FIG. 4B is a schematic diagram of the fuel system of FIG. 4A showing agaseous fuel source in communication with a carburetor of the generatorof FIG. 1 consistent with the second position of the switch as shown inFIG. 3, according to an embodiment of the invention.

FIG. 5 is a perspective view of a fuel delivery system for the dual fuelgenerator of FIG. 1, according to an embodiment of the invention.

FIG. 6 is a side view of a fuel delivery system for the dual fuelgenerator of FIG. 1, according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The operating environment of the invention is described with respect toa dual fuel generator. However, it will be appreciated by those skilledin the art that the invention is equally applicable for use with anydual fuel internal combustion engine. Moreover, the invention will bedescribed with respect to a dual fuel generator configured to operate ona liquid fuel and a gaseous fuel. However, one skilled in the art willfurther appreciate that the invention is equally applicable for use withother fuel combinations for dual fuel generators and internal combustionengines.

Referring to FIG. 1, a dual fuel generator 20 is coupled to a fueldelivery system 22, in accordance with an embodiment of the invention.Dual fuel generator 20 includes an internal combustion engine (notshown) within housing 21 at one end 24, operatively connected to analternator also enclosed in housing 21 at another end 26, byconventional means. Dual fuel generator 20 is configured to operate ondifferent fuels via either a first fuel source 28 or a second fuelsource 30. In an exemplary embodiment of the invention, first fuelsource 28 is a liquid fuel and second fuel source 30 is a gaseous fuel.The liquid fuel may be gasoline and the gaseous fuel may be liquidpetroleum gas (LPG). Each can selectively operate the generator asdesired and controlled by an operator. For instance, generator 20 mayoperate on gasoline for a first period of operation and then switch toLPG for a second period of operation. However, it is contemplated thatdual fuel generator 20 is configured to operate on fuels other thangasoline and LPG (e.g., natural gas, biodiesel, etc.), and thus thescope of the invention is not meant to be limited strictly to a dualfuel arrangement where first fuel source 28 provides gasoline and secondfuel source 30 provides LPG.

In one embodiment of the invention, dual fuel generator 20 includes agasoline tank 32 or, generally, a liquid fuel tank, located inside cover21 onboard generator 20 to provide gasoline to the engine as first fuelsource 28. Gasoline tank 32 connects to a first fuel line to providegasoline to the carburetor to run the engine, as will later be describedwith reference to FIGS. 4A and 4B. Generator 20 is also coupled to apressurized fuel container 34, or a pressurized fuel source, located offboard generator 20 to provide LPG to the engine as second fuel source30. Pressurized fuel container 34 is coupled to generator 20 with an LPGsupply hose 36. LPG supply hose 36 is coupled to a second fuel linewithin generator 20 to provide LPG to the carburetor to run the engine.Dual fuel generator 20 includes a mechanical fuel lockout switch 38 forselecting a desired fuel to be provided to the engine. The mechanicalfuel lockout switch 38 is actuated to select first fuel source 28 whenin a first position, as shown in FIG. 2, and alternately to selectsecond fuel source 30 when in a second position, as shown in FIG. 3.

Referring back to FIG. 1, in an exemplary embodiment, fuel 30 frompressurized fuel container 34 is regulated using a fuel regulator system39 for delivery to the engine. Fuel regulator system 39 includes one ormore pressure regulators that reduce and control the pressure of thefuel from pressurized fuel container 34 and delivers fuel at a desiredpressure for operation of the engine. Fuel regulator system 39 has aninlet 41 operatively coupled to a service valve 40 of pressurized fuelcontainer 34 and an outlet 43 coupled to LPG supply hose 36. Fuelregulator system 39 includes a primary pressure regulator 42 coupled topressurized fuel container 34 and a secondary pressure regulator 44.Primary pressure regulator 42 protects downstream components from highpressure of pressurized fuel container 34. Primary pressure regulator 42receives LPG through service valve 40 of pressurized fuel container 34and reduces the pressure of the LPG to a first stage. In one embodimentof the invention, the first stage may be delivered directly to generator20 at a pressure required for operation of the engine.

In an exemplary embodiment of the invention, fuel regulator system 39includes secondary pressure regulator 44 coupled to the outlet ofprimary pressure regulator 42 in order to use standard “off-the-shelf”components. Typically, the primary pressure regulator is mounted on theLPG tank, while the secondary pressure regulator is mounted on thecomponent using the fuel, such as an engine or grill. Here, sincegenerator 20 can be used as a gasoline only generator, secondarypressure regulator 44 is mounted off-board the generator to reduce sizeand cost of the generator. Secondary pressure regulator 44 receives LPGfrom primary pressure regulator 42 and further reduces the pressure ofLPG to a second stage to be delivered to generator 20. In a system withtwo regulators, primary pressure regulator 42 regulates fuel receivedfrom pressurized fuel container 34 and reduces the pressure of the fuelto a level required for operation of secondary pressure regulator 44.Secondary pressure regulator 44 regulates fuel received from primarypressure regulator 42 and further reduces the pressure of the fuel to alevel required for operation of generator 20. In addition, primarypressure regulator 42 may compensate for varying tank pressure as fuelis depleted while secondary pressure regulator 44 may compensate forvarying demand from generator 20.

In accordance with an exemplary embodiment of the invention, fuelregulator system 39 includes both the primary and secondary regulators,or a custom single regulator, but in any case is located remotely, oroff-board, from dual fuel generator 20. Fuel regulator system 39 may bedirectly mounted to pressurized fuel container 34 using a regulatormounting bracket 46. Regulator mounting bracket 46 has mountinglocations for primary pressure regulator 42 and secondary pressureregulator 44. Regulator mounting bracket 46 also has a securingmechanism 48 to secure regulator mounting bracket 46 to pressurized fuelcontainer 34.

In another embodiment of the invention, primary pressure regulator 42 ismounted on regulator mounting bracket 46 while secondary pressureregulator 44 could be mounted on or near generator 20. In yet anotherembodiment of the invention, a dual stage regulator may regulate thefuel received from pressurized fuel container 34 and deliver fuel at apressure required for operation of generator 20. Such a dual stageregulator may regulate the fuel to the second stage within a singlestructure. The dual stage regulator may be mounted directly on fuelcontainer 34.

Referring to FIG. 2, a detail view of a portion of generator 20 of FIG.1 depicts mechanical fuel lockout switch 38 in a first position 38(a),in accordance with an embodiment of the invention. In this position,mechanical fuel lockout switch 38 provides gasoline flow from gasolinetank 32 to the engine while preventing connection of an LPG supply lineto fuel inlet 59 of the second fuel line, as will later be discussed indetail with reference to FIGS. 4A and 4B. Still referring to FIG. 2,mechanical fuel lockout switch 38 provides a combination liquid fuelshutoff valve and a gaseous fuel supply lockout that preventssimultaneous delivery of fuel to the engine from gasoline tank 32 andpressurized fuel container 34, FIG. 1. As such, mechanical fuel lockoutswitch 38 provides a fuel selector to ensure only the selected fuel isprovided to dual fuel generator 20.

Mechanical fuel lockout switch 38, FIG. 2, includes mechanical fuelvalve 54 actuatable between first position 38(a) as shown in FIG. 2 andsecond position 38(b) as shown in FIG. 3 to selectively control fuelflow to the dual fuel engine from first fuel source 28 through a firstfuel line and second fuel source 30 through a second fuel line 36.Mechanical fuel lockout switch 38 may also include fuel lockoutapparatus 58 coupled to mechanical fuel valve 54 to communicate fuelsources individually to generator 20. In one embodiment of theinvention, fuel lockout apparatus 58 communicates first fuel source 28to the engine by actuating mechanical fuel valve 54 to first position38(a) to open the first fuel line as shown in FIG. 2, and communicatessecond fuel source 30 to the engine by actuating mechanical fuel valve54 to second position 38(b) to open communication of the second fuelsource 30 to the engine as shown in FIG. 3. Referring back to FIG. 2,when mechanical fuel valve 54 is in first position 38(a), fuel lockoutapparatus 58 communicates first fuel source 28 to the dual fuel engineand prevents communication between the second fuel source and the dualfuel engine.

In an exemplary embodiment of the invention, mechanical fuel valve 54controls the flow of LPG to the engine by actuating fuel lockoutapparatus 58 to block or unblock fuel inlet 59 for the second fuelsource. Mechanical fuel valve 54 is coupled to the first fuel line, asshown in FIGS. 4A and 4B, and therefore can control the flow of gasolineto the engine by opening and closing the first fuel line. When themechanical fuel valve 54, FIG. 2, is in the first position 38(a),gasoline flows from the gasoline tank to the engine and the fuel lockoutapparatus 58 blocks the fuel inlet 59. Accordingly, fuel lockoutapparatus 58 prevents LPG flow to generator 20 when the mechanical fuelvalve 54 is in first position 38(a) wherein the engine is operated ongasoline.

Mechanical fuel valve 54 includes a fuel valve handle 56 to control theopening and closing of the valve. Fuel valve handle 56 is movablebetween first position 38(a) as shown in FIG. 2 and second position38(b) as shown in FIG. 3. Mechanical fuel valve 54 opens the first fuelline (to enable liquid fuel flow to the engine) when fuel valve handle56 is in the first position, and mechanical fuel valve 54 closes thefirst fuel line (to prevent liquid fuel flow to the engine) when fuelvalve handle 56 is in the second position. Thus, when fuel valve handle56 is in first position 38(a) as shown in FIG. 2, mechanical fuel valve54 opens the first fuel line and allows gasoline from gasoline tank 32to flow to the engine.

Fuel valve handle 56 is coupled to fuel lockout apparatus 58. Fuel valvehandle 56 actuates with fuel lockout apparatus 58 to prevent LPG flow togenerator 20 when gasoline flow to the generator is enabled. Fuellockout apparatus 58 is controlled by fuel valve handle 56 so thatmoving fuel valve handle 56 to the first position causes fuel lockoutapparatus 58 to block fuel inlet 59 for LPG, and moving fuel valvehandle 56 to the second position causes fuel lockout apparatus 58 tounblock fuel inlet 59 for LPG.

In an exemplary embodiment of the invention, fuel valve handle 56rotates between the first position and the second position and fuellockout apparatus 58 is rigidly coupled to the rotating handle. Fuellockout apparatus 58 may include a fuel inlet cover 61, which may be aflange, coupled to fuel valve handle 56 so that fuel inlet cover 61rotates with the handle. Fuel inlet cover 61 extends radially outwardfrom fuel valve handle 56 and sweeps over fuel inlet 59 for LPG as fuelvalve handle 56 rotates. That is, fuel inlet cover 61 rotatestransversely across fuel inlet 59 and blocks access thereto.Accordingly, fuel inlet cover 61 prevents LPG flow to generator 20 whenfuel valve handle 56 is in first position 38(a) to allow gasoline to runthe engine.

Referring to FIG. 3, a detail view of a portion of generator 20 of FIG.1 depicts mechanical fuel lockout switch 38 in a second position 38(b),in accordance with an embodiment of the invention. In this position, themechanical fuel lockout switch 38 provides a disconnect to stop gasolineflow from gasoline tank 32 to the engine while allowing connection ofLPG supply hose 36 to fuel inlet 59 of the second fuel line. FIG. 3further shows LPG supply hose 36 coupling second fuel source 30 togenerator 20 to deliver LPG to run the generator.

Mechanical fuel lockout switch 38 includes mechanical fuel valve 54coupled to fuel lockout apparatus 58 to prevent gasoline flow togenerator 20 when LPG from the LPG service hose 36 is supplied to theengine. In one embodiment of the invention, actuation of mechanical fuelvalve 54 to second position 38(b) causes fuel lockout apparatus 58 toallow communication of second fuel source 30 to the dual fuel engine,and interrupts the first fuel source 28 communication with the dual fuelengine. The position of fuel lockout apparatus 58 prevents the fuelvalve handle 56 from moving to first position 38(a) (FIG. 2) while LPGsupply hose 36 is connected to generator 20.

A quick-disconnect hose coupling 50, also referred to as a quick-connecthose coupling, connects LPG supply hose 36 to generator 20 so that LPGsupply hose 36 may be quickly attached and detached from generator 20.Hose coupling 50 has a first end 50 a mounted on the external surface ofgenerator 20 and coupled to supply the second fuel to the engine. Hosecoupling 50 has a second end 50 b coupled to the outlet of LPG supplyhose 36. Hose coupling 50 has a valve that opens when the couplings areengaged and closes when the couplings are disengaged. As such,quick-disconnect hose coupling 50 automatically opens when connected toenable fuel flow from LPG supply hose 36 to the engine. Hose coupling 50automatically disconnects fluid communication when disconnected.Accordingly, when the supply hose is detached from generator 20, thecoupling 50 is automatically closed so that fuel does not escape andunwanted air does not enter the fuel system.

In one embodiment, fuel inlet cover 61 is coupled to fuel valve handle56 so that it is spaced apart from the surface of generator 20 toprovide clearance for first end 50 a of the quick-disconnect hosecoupling 50 that protrudes from the surface of generator 20. As shown inFIG. 2, fuel inlet cover 61 blocks off first end 50 a of thequick-disconnect hose coupling when fuel valve handle 56 is rotated tofirst position 38(a) to enable gasoline flow so that fuel inlet cover 61prevents connection of LPG supply hose 36 (FIG. 3) to generator 20. Asshown in FIG. 3, fuel inlet cover 61 uncovers first end 50 a of thequick-disconnect hose coupling 50 when fuel valve handle 56 is rotatedto second position 38(b) to disable gasoline flow so that fuel inletcover 61 permits connection of LPG supply hose 36 to generator 20.

To operate generator 20 on LPG, fuel valve handle 56 is turned to secondposition 38(b) to disable the flow of gasoline to the engine and toexpose first end 50 a of hose coupling 50 on generator 20. LPG supplyhose 36 is then connected to generator 20 via hose coupling 50 to enablethe flow of LPG to the engine. To operate generator 20 on gasoline, LPGsupply hose 36 is disconnected from generator 20 via hose coupling 50 todisable the flow of LPG to the engine and to unblock fuel valve handle56 from rotating to the first position. As shown in FIG. 2, fuel valvehandle 56 is then turned to first position 38(a) to enable the flow ofgasoline to generator 20.

Referring to FIG. 4A, a schematic diagram of a fuel system for a dualfuel engine shows mechanical fuel lockout switch 38 in first position38(a) to provide communication between the first fuel source 28 and dualfuel carburetor 62, according to an embodiment of the invention.Mechanical fuel lockout switch 38 prevents communication between secondfuel source 30 and dual fuel carburetor 62 when the switch is in firstposition 38(a). In one embodiment of the invention, first fuel source 28includes a gasoline tank 32 to provide gasoline to carburetor 62 througha first fuel line 66, and second fuel source 30 includes a propane orLPG tank 68 to provide propane or LPG to carburetor 62 through a secondfuel line 70. Accordingly, first fuel line 66 may be a liquid fuel lineand second fuel line 70 may be a gaseous fuel line.

Mechanical fuel lockout switch 38 includes a mechanical fuel valve 54actuatable between first position 38(a) as shown in FIG. 4A and secondposition 38(b) as shown in FIG. 4B to selectively control fuel flow tothe dual fuel engine from first fuel source 28 through first fuel line66 and second fuel source 30 through second fuel line 70. Referring backto FIG. 4A, mechanical fuel valve 54 selectively controls fuel flowthrough first fuel line 66 by opening the line when the mechanical fuellockout switch 38 actuates to first position 38(a). Mechanical fuelvalve 54 may be coupled to fuel lockout apparatus 58 that actuates withmechanical fuel valve 54 to block and unblock fuel inlet 59 of secondfuel line 70. First end 50 a of the quick-disconnect hose coupling islocated at fuel inlet 59 and a mating end 50 b of the quick-disconnecthose coupling is coupled to the propane or LPG tank 68. Actuation ofmechanical fuel valve 54 to first position 38(a) causes fuel lockoutapparatus 58 to block fuel inlet 59 to prevent coupling the first end 50a and second end 50 b of the quick-disconnect hose coupling together,and actuation of mechanical fuel valve 54 to another position causesfuel lockout apparatus 58 to unblock fuel inlet 59 to permit attachingfirst end 50 a and second end 50 b together.

In one embodiment of the invention, a fuel cut solenoid 63 couples tocarburetor 62 to regulate liquid fuel flow into a main nozzle within thecarburetor. Fuel cut solenoid 63 is advantageous to control liquid fuelflow downstream of a float bowl in the carburetor and can stop fuel flowto the engine immediately after ignition shutdown. As such, fuel cutsolenoid 63 prevents the engine from drawing in fuel from the float bowlwhile the engine shuts off. Fuel cut solenoid 63 also traps fuel in thefloat bowl to eliminate delay in filling the bowl when starting theengine on liquid fuel, and prevents liquid fuel flow from the float bowlto the engine when starting on gaseous fuel.

Fuel cut solenoid 63 may regulate fuel flow through multiple fuel linesin carburetor 62 that provide fuel from the float bowl to the engine.For instance, carburetor 62 may have a main fuel line and an idle fuelline that receive fuel from the float bowl. Fuel cut solenoid 63 maycontrol fuel flow through all of the fuel lines that receive fuel fromthe float bowl or may regulate only some of the fuel lines. As such,fuel cut solenoid 63 may block fuel flow through the main fuel linewhile small amounts of fuel can flow through the idle fuel line.

Fuel cut solenoid 63 preferably operates as a normally closed valve thatopens when powered by a 12 volt battery 65, although fuel cut solenoid63 may also be operated as a normally open valve. The normally closedvalve is opened for gasoline mode to allow gasoline flow to the engineand closed for LPG mode to prevent gasoline flow to the engine. Fuel cutsolenoid 63 is operated by an electrical switch 67 which may bemechanically actuated and controlled by mechanical fuel lockout switch38. As such, actuation of mechanical fuel lockout switch 38 to firstposition 38(a) closes electrical switch 67 to power and open fuel cutsolenoid 63 as represented in FIG. 4A, and actuation of mechanical fuellockout switch 38 to second position 38(b) opens electrical switch 67 tointerrupt power and close fuel cut solenoid 63 as represented in FIG.4B.

Referring to FIG. 4B, a schematic diagram of a fuel system for a dualfuel engine shows mechanical fuel lockout switch 38 in second position38(b) to provide communication between second fuel source 30 and dualfuel carburetor 62, according to an embodiment of the invention.Mechanical fuel lockout switch 38 prevents communication between firstfuel source 28 and dual fuel carburetor 62 when the switch is in secondposition 38(b). The dual fuel engine has a first fuel line 66 to providefuel from first fuel source 28 to carburetor 62 and a second fuel line70 to provide fuel from second fuel source 30 to carburetor 62.

Mechanical fuel lockout switch 38 includes mechanical fuel valve 54 thatselectively controls fuel flow through first fuel line 66 by closing theline when mechanical fuel lockout switch 38 actuates to second position38(b). Mechanical fuel lockout switch 38 may also include a mechanicallockout apparatus 58 to block and unblock fuel inlet 59 of the secondfuel line 70. Fuel inlet 59 may include first end 50 a of thequick-connect hose coupling mounted on the generator and coupled tosecond fuel line 70. Second end 50 b of the quick-connect hose couplingis coupled to the outlet of second fuel source 30, and the first end 50a mates with second end 50 b to quickly attach propane or LPG tank 68 tosecond fuel line 70. Fuel lockout apparatus 58 may also hold mechanicalfuel lockout switch 38 in second position 38(b) when the propane or LPGtank 68 is coupled to the engine via the ends 50 a, 50 b of thequick-connect hose coupling.

Fuel cut solenoid 63 couples to carburetor 62 to regulate liquid fuelflow through the carburetor as described with respect to FIG. 4A. FIG.4B shows electrical switch 67 opened to interrupt power and close fuelcut solenoid 63 for LPG mode when mechanical fuel lockout switch 38 isin second position 38(b).

FIGS. 4A and 4B depict an embodiment where mechanical fuel valve 54operates along first fuel line 66 to provide a flow path for first fuelsource 28 to carburetor 62 when the valve is in first position 38(a).That is, mechanical fuel valve 54 may control a single fuel line thatruns through the valve while operating fuel lockout apparatus 58 tocontrol fuel flow through second fuel line 70. Embodiments of theinvention also contemplate mechanical fuel valve 54 configured tooperate along second fuel line 70 to provide a flow path for second fuelsource 30 to carburetor 62 when the valve is in second position 38(b).Mechanical fuel valve 54 may be configured to control multiple fuellines that run through the valve according to embodiments of theinvention.

Referring now to FIG. 5, a perspective view of fuel delivery system 22for dual fuel generator 20 of FIG. 1 is shown, in accordance with anembodiment of the invention. Fuel delivery system 22 includes a mountingarrangement for fuel regulator system 39. The mounting arrangementincludes regulator mounting bracket 46 for mounting fuel regulatorsystem 39. Regulator mounting bracket 46 extends around the outerperiphery of collar 136 on pressurized fuel container 34. Regulatormounting bracket 46 has securing mechanism 48 to secure to collar 136.In one embodiment, securing mechanism 48 is a rigid component thatextends inward from regulator mounting bracket 46 with a slot forreceiving collar 136 to hold regulator mounting bracket 46 to collar136.

Regulator mounting bracket 46 provides mounting locations for pressureregulators. In one embodiment, regulator mounting bracket 46 is made ofsheet metal bent in two locations to provide a central panel 138, afirst outer panel 140, and a second outer panel 142 for mounting theregulators. The panels may be angled from each other such that regulatormounting bracket 46 fits around collar 136. Primary pressure regulator42 mounts on first outer panel 140 and secondary pressure regulator 44mounts on second outer panel 142. The panels are sized according totheir respective regulators. Accordingly, second outer panel 142 islarger than first outer panel 140 if secondary pressure regulator 44 islarger than primary pressure regulator 42. Panels 140, 142 havefasteners or openings to receive fasteners to couple respectiveregulators 42, 44 to the panels. Regulator mounting bracket 46 rests ontop of pressurized fuel container 34 and engages the periphery of collar136 to support fuel regulator system 39 on the container.

In one embodiment of the invention, primary pressure regulator 42couples to two ninety degree elbows 144, 145 to reach around collar 136in order to couple to service valve 40. The two elbows 144, 145 arejoined by a hose or pipe 146 that leads from elbow 144 at service valve40 to elbow 145 at the outer periphery of collar 136. The outlet ofprimary pressure regulator 42 couples to a hose 148 that extends toanother ninety degree elbow 150 coupled to the inlet of secondarypressure regulator 44. Secondary pressure regulator 44 couples to LPGsupply hose 36. Pressurized fuel container 34 may be strapped to a dolly152.

Referring now to FIG. 6, a side view of another fuel delivery system 22for dual fuel generator 20 of FIG. 1 is shown, in accordance with anembodiment of the invention. Fuel delivery system 22 includes a mountingarrangement for fuel regulator system 39. The mounting arrangementincludes a regulator mounting structure 154 for mounting fuel regulatorsystem 39 to pressurized fuel container 34. Regulator mounting structure154 includes a cylinder 156 that surrounds the circumference ofpressurized fuel container 34 to secure regulator mounting structure 154radially along the circumference of pressurized fuel container 34.Cylinder 156 couples to a dome 158 to support cylinder 156 relative tothe top of pressurized fuel container 34. Dome 158 has a central opening160 through which collar 136 of pressurized fuel container 34 extends.Collar 136 of pressurized fuel container 34 extends through dome 158 sothat service valve 40 is easily accessible from above regulator mountingstructure 154 and so that dome 158 sits on pressurized fuel container 34around collar 136.

Regulator mounting structure 154 supports pressure regulators around theouter circumference of cylinder 156. In some embodiments of theinvention, a dual stage pressure regulator 162 functions as both aprimary pressure regulator and a secondary pressure regulator in asingle integral component, and dual stage pressure regulator 162 may bemounted on regulator mounting structure 154. In other embodiments in ofthe invention, primary pressure regulator 42 (FIG. 5) is mounted toservice valve 40 while secondary pressure regulator 44 (FIG. 5) ismounted on regulator mounting structure 154. Alternatively, both primarypressure regulator 42 (FIG. 5) and secondary pressure regulator 44 (FIG.5) may be mounted on regulator mounting structure 154.

Fuel regulator system 39 may be coupled to service valve 40 by aflexible connector called a pigtail 164. Pigtail 164 absorbs shock inthe system from pressure surges and from movement of downstreamcomponents. Pigtail 164 can be looped to conserve space and thereforepressurized fuel container 34 is referred to as an LPG pig. Accordingly,regulator mounting structure 154 is referred to as a pig hat because itfits on the LPG pig. Pressurized fuel container 34 may be secured to aplatform or mobile cart 64 for stability or transportation. In anotherembodiment, a regulator mounting device, including regulator mountingstructure 154 or regulator mounting bracket 46 (FIG. 5), is secureddirectly to a platform or a mobile cart.

Beneficially, embodiments of the invention provide for a mechanical fuellockout switch to ensure that two fuels are not simultaneously deliveredto a dual fuel internal combustion engine. Embodiments of the inventionalso provide for a dual fuel generator with a remotely mounted gaseousfuel regulator system.

Therefore, according to one embodiment of the invention, a mechanicalfuel lockout switch for a dual fuel engine includes a mechanical fuelvalve actuatable between a first position and a second position toselectively control fuel flow to the dual fuel engine from a first fuelsource through a first fuel line and a second fuel source through asecond fuel line. The mechanical fuel lockout switch also includes afuel lockout apparatus coupled to the mechanical fuel valve. Themechanical fuel lockout switch communicates the first fuel source to thedual fuel engine and prevents communication between the second fuelsource and the dual fuel engine when the mechanical fuel valve is in thefirst position, and communicates the second fuel source to the dual fuelengine and interrupts the first fuel source communication with the dualfuel engine when in the second position.

According to another embodiment of the invention, a dual fuel generatorand fuel delivery system includes a dual fuel generator configured tooperate on a liquid fuel supplied from a liquid fuel source through aliquid fuel line and a gaseous fuel supplied from a pressurized fuelsource through a gaseous fuel line. The dual fuel generator and fueldelivery system also includes a fuel regulator system located off boardthe dual fuel generator. The fuel regulator system includes a primarypressure regulator coupled to a service valve of the pressurized fuelsource and configured to regulate the fuel supplied from the pressurizedfuel source to a reduced pressure. The fuel regulator system alsoincludes a secondary pressure regulator coupled to the primary pressureregulator and configured to regulate the gaseous fuel supplied from theprimary pressure regulator to a desired pressure for delivery throughthe gaseous fuel line to operate the dual fuel generator. The dual fuelgenerator and fuel delivery system further includes a mechanical fuelvalve actuatable between a first position and a second position toselectively control fuel flow to the dual fuel generator from the liquidfuel source through the liquid fuel line and the pressurized fuel sourcethrough the gaseous fuel line.

According to yet another embodiment of the invention, a method ofassembling a mechanical fuel lockout switch for an internal combustionengine includes providing an internal combustion engine configured tooperate on a fuel from a first fuel source and a different fuel from asecond fuel source. The method also includes coupling a mechanical fuelvalve to the internal combustion engine actuatable between a firstposition and a second position to selectively control fuel flow to theinternal combustion engine from the first fuel source through a firstfuel line and the second fuel source through a second fuel line. Themethod further includes coupling a fuel lockout apparatus to themechanical fuel valve. When the mechanical fuel valve is in the firstposition, the fuel lockout apparatus communicates the first fuel sourceto the internal combustion engine and prevents the second fuel sourcefrom coupling to the internal combustion engine, and actuation of themechanical fuel valve to the second position causes the fuel lockoutapparatus to permit the second fuel source to couple to the internalcombustion engine, and interrupts the first fuel source communicationwith the internal combustion engine.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A generator and fuel delivery system comprising:a generator free of any pressure regulator and configured to operate ona gaseous fuel supplied from a pressurized fuel source through a gaseousfuel line; a fuel regulator system located off-board the generator andcomprising a first stage and a second stage, the fuel regulator systemconfigured to: regulate the gaseous fuel supplied from the pressurizedfuel source in the first stage, the gaseous fuel regulated down to areduced pressure in the first stage; and regulate the reduced pressuregaseous fuel in the second stage, the reduced pressure gaseous fuel fromthe first stage regulated down to a desired pressure in the second stagefor delivery through the gaseous fuel line to operate the generator. 2.The generator and fuel delivery system of claim 1 wherein the first andsecond stages comprise a dual stage regulator configured to regulate thegaseous fuel supplied from the pressurized fuel source and regulate thereduced pressure gaseous fuel.
 3. The generator and fuel delivery systemof claim 2 wherein the dual stage regulator is mounted directly onto thepressurized fuel source, off-board from the generator.
 4. The generatorand fuel delivery system of claim 1 wherein the generator comprises adual fuel generator configured to operate on the gaseous fuel and on aliquid fuel, the liquid fuel supplied from a liquid fuel source througha liquid fuel line.
 5. The generator and fuel delivery system of claim 4further comprising a mechanical fuel valve actuatable between a firstposition and a second position to selectively control fuel flow to thedual fuel generator from the liquid fuel source through the liquid fuelline and the pressurized fuel source through the gaseous fuel line. 6.The generator and fuel delivery system of claim 5 further comprising afuel lockout apparatus coupled to the mechanical fuel valve; wherein,when the mechanical fuel valve is in the first position, the fuellockout apparatus communicates the liquid fuel source to the dual fuelgenerator and prevents the pressurized fuel source from coupling to thedual fuel generator; and wherein, when the mechanical fuel valve is inthe second position, the fuel lockout apparatus permits the pressurizedfuel source to couple to the dual fuel generator and interrupts theliquid fuel source communication with the dual fuel generator.
 7. Thegenerator and fuel delivery system of claim 1, wherein the first stagecomprises a primary pressure regulator and the second stage comprises asecondary pressure regulator; and wherein the generator and fueldelivery system further comprises a quick-connect hose couplingincluding: a first end coupled to an outlet of the secondary pressureregulator; and a second end coupled to an inlet of the gaseous fuel lineto couple the secondary pressure regulator to the gaseous fuel line. 8.The generator and fuel delivery system of claim 7, further comprising aregulator mounting device secured to the pressurized fuel source with atleast the secondary pressure regulator mounted on the regulator mountingdevice.
 9. The generator and fuel delivery system of claim 8, whereinthe primary pressure regulator is mounted on the regulator mountingdevice.
 10. The generator and fuel delivery system of claim 9, whereinthe pressurized fuel source comprises a pressurized fuel containerhaving a collar; and wherein the regulator mounting device secures tothe collar so that the primary and secondary pressure regulators arepositioned adjacent each other along an outer periphery of the collar.11. A generator and fuel delivery system comprising: a generatorconfigured to operate on a gaseous fuel supplied from a pressurized fuelsource through a gaseous fuel line; a fuel regulator system locatedoff-board the generator and comprising a first stage and a second stage,the fuel regulator system configured to: regulate the gaseous fuelsupplied from the pressurized fuel source in the first stage, thegaseous fuel regulated down to a first reduced pressure in the firststage; and regulate the gaseous fuel output from the first stage in thesecond stage, the first reduced pressure gaseous fuel from the firststage being regulated down to a second reduced pressure in the secondstage for delivery through the gaseous fuel line to operate thegenerator; wherein the fuel regulator system outputs gaseous fuel to thegenerator for operation of the engine at the second reduced pressure.12. The generator and fuel delivery system of claim 11 wherein the firstand second stages comprise a dual stage regulator configured to regulatethe gaseous fuel supplied from the pressurized fuel source and regulatethe reduced pressure gaseous fuel.
 13. The generator and fuel deliverysystem of claim 12 wherein the dual stage regulator is mounted directlyonto the pressurized fuel source, off-board from the generator.
 14. Thegenerator and fuel delivery system of claim 11 wherein the generatorcomprises a dual fuel generator configured to operate on the gaseousfuel and on a liquid fuel, the liquid fuel supplied from a liquid fuelsource through a liquid fuel line.
 15. The generator and fuel deliverysystem of claim 14 further comprising a mechanical fuel valve actuatablebetween a first position and a second position to selectively controlfuel flow to the dual fuel generator from the liquid fuel source throughthe liquid fuel line and the pressurized fuel source through the gaseousfuel line.
 16. A dual fuel generator and fuel delivery systemcomprising: a dual fuel generator configured to operate on a liquid fuelsupplied from a liquid fuel source through a liquid fuel line and agaseous fuel supplied from a pressurized fuel source through a gaseousfuel line; a fuel regulator system located off board the dual fuelgenerator, the fuel regulator system comprising: a primary pressureregulator coupled to a service valve of the pressurized fuel source andconfigured to regulate the fuel supplied from the pressurized fuelsource to a first reduced pressure; and a secondary pressure regulatorcoupled to the primary pressure regulator and configured to regulate thegaseous fuel supplied from the primary pressure regulator down from thefirst reduced pressure to a second reduced pressure for delivery throughthe gaseous fuel line to operate the dual fuel generator; wherein thefuel regulator system outputs gaseous fuel to the dual fuel generatorfor operation thereof at the second reduced pressure.
 17. The dual fuelgenerator and fuel delivery system of claim 16 wherein the primary andsecondary pressure regulators are integral components of a dual stagepressure regulator.
 18. The dual fuel generator and fuel delivery systemof claim 16, further comprising a quick-connect hose coupling including:a first end coupled to an outlet of the secondary pressure regulator;and a second end coupled to an inlet of the gaseous fuel line to couplethe secondary pressure regulator to the gaseous fuel line.
 19. The dualfuel generator and fuel delivery system of claim 16, wherein thepressurized fuel source comprises a pressurized fuel container having acollar; and wherein the regulator mounting device secures to the collarso that the primary and secondary pressure regulators are positionedadjacent each other along an outer periphery of the collar.